<?php
/*
 *  $Id: Oracle.php 7490 2010-03-29 19:53:27Z jwage $
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.doctrine-project.org>.
 */

/**
 * Doctrine_Connection_Oracle
 *
 * @package     Doctrine
 * @subpackage  Connection
 * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @link        www.doctrine-project.org
 * @since       1.0
 * @version     $Revision: 7490 $
 * @author      Konsta Vesterinen <kvesteri@cc.hut.fi>
 */
class Doctrine_Connection_Oracle extends Doctrine_Connection_Common
{
	/**
	 * @var string $driverName                  the name of this connection driver
	 */
	protected $driverName = 'Oracle';

	public function __construct(Doctrine_Manager $manager, $adapter)
	{
		$this->supported = array(
                          'sequences'            => true,
                          'indexes'              => true,
                          'summary_functions'    => true,
                          'order_by_text'        => true,
                          'current_id'           => true,
                          'affected_rows'        => true,
                          'transactions'         => true,
                          'savepoints'           => true,
                          'limit_queries'        => true,
                          'LOBs'                 => true,
                          'replace'              => 'emulated',
                          'sub_selects'          => true,
                          'auto_increment'       => false, // implementation is broken
                          'primary_key'          => true,
                          'result_introspection' => true,
                          'prepared_statements'  => true,
                          'identifier_quoting'   => true,
                          'pattern_escaping'     => true,
		);

		$this->properties['sql_file_delimiter']    = "\n/\n";
		$this->properties['number_max_precision']  = 38;
		$this->properties['max_identifier_length'] = 30;

		parent::__construct($manager, $adapter);

		// moving properties to params to make them changeable by user
		// VARCHAR2 allowed length is 4000 BYTE. For UTF8 strings is better to use 1000 CHAR
		$this->setParam('varchar2_max_length', 4000);
		// Oracle's default unit for char data types is BYTE. For UTF8 string it is better to use CHAR
		$this->setParam('char_unit', null);
	}

	/**
	 * Sets up the date/time format
	 *
	 */
	public function setDateFormat($format = 'YYYY-MM-DD HH24:MI:SS')
	{
		$this->exec('ALTER SESSION SET NLS_DATE_FORMAT = "' . $format . '"');
	}

	/**
	 * Adds an driver-specific LIMIT clause to the query
	 *
	 * @param string $query         query to modify
	 * @param integer $limit        limit the number of rows
	 * @param integer $offset       start reading from given offset
	 * @return string               the modified query
	 */
	public function modifyLimitQuery($query, $limit = false, $offset = false, $isManip = false)
	{
		return $this->_createLimitSubquery($query, $limit, $offset);
	}

	private function _createLimitSubquery($query, $limit, $offset, $column = null)
	{
		$limit = (int) $limit;
		$offset = (int) $offset;
		if (preg_match('/^\s*SELECT/i', $query)) {
			if ( ! preg_match('/\sFROM\s/i', $query)) {
				$query .= " FROM dual";
			}
			if ($limit > 0) {
				$max = $offset + $limit;
				$column = $column === null ? '*' : $this->quoteIdentifier($column);
				if ($offset > 0) {
					$min = $offset + 1;
					$query = 'SELECT b.'.$column.' FROM ( '.
                                 'SELECT a.*, ROWNUM AS doctrine_rownum FROM ( '
                                 . $query . ' ) ' . $this->quoteIdentifier('a') . ' '.
                              ' ) ' . $this->quoteIdentifier('b') . ' '.
                              'WHERE doctrine_rownum BETWEEN ' . $min .  ' AND ' . $max;
				} else {
					$query = 'SELECT a.'.$column.' FROM ( ' . $query .' ) a WHERE ROWNUM <= ' . $max;
				}
			}
		}
		return $query;
	}

	/**
	 * Creates the SQL for Oracle that can be used in the subquery for the limit-subquery
	 * algorithm.
	 */
	public function modifyLimitSubquery(Doctrine_Table $rootTable, $query, $limit = false,
	$offset = false, $isManip = false)
	{
		// NOTE: no composite key support
		$columnNames = $rootTable->getIdentifierColumnNames();
		if (count($columnNames) > 1) {
			throw new Doctrine_Connection_Exception("Composite keys in LIMIT queries are "
			. "currently not supported.");
		}
		$column = $columnNames[0];
		return $this->_createLimitSubquery($query, $limit, $offset, $column);
	}

	public function getTmpConnection($info)
	{
		return clone $this;
	}
}